The MGM Grand in Las Vegas is expanding the wellness program at its Strip hotel, offering healthful snacks, purified tap water and an air purification system, among other perks, to guests who choose those accommodations.

The entire 14thfloor of the MGM Grand’s main tower now boasts rooms and suites embracing the hotel’s Stay Well program. A total of 171 rooms — more than four times the number with which Stay Well began in October — offer various special features.

Wellness experts at Delos created the 17 in-room enhancements. They include:

An air purification system that uses HEPA technology to reduce allergens, pathogens and toxins.

A mini-bar stocked with items such as almonds, coconut water and yogurt-covered raisins.